Methods and systems for determining a fault in a gas heater channel

ABSTRACT

Systems and methods for determining a fault in a gas heater channel are described. One of the methods includes receiving measured parameters associated with a plurality of heater elements of the gas heater channel. The gas heater channel transfers one or more gases from a gas supply to a plasma chamber. The method further includes calculating a measured parallel resistance of the plurality of heater elements from the measured parameters, comparing the measured parallel resistance to an ideal parallel resistance of the heater elements of the gas heater channel, and determining based on the comparison that a portion of the gas heater channel is inoperational. The method includes selecting an identity of one of the heater elements from a correspondence between a plurality of identities of the heater elements and the measured parallel resistance.

FIELD

The present embodiments relate to systems and methods for determining afault in a gas heater channel.

BACKGROUND

Plasma systems are used to perform various operations on a wafer. Forexample, the plasma systems are used to clean the wafer, etch the wafer,or deposit materials on the wafer.

To perform the operation, a gas is supplied to a plasma chamber. The gasis heated before being provided to the plasma chamber.

It is in this context that embodiments described in the presentdisclosure arise.

SUMMARY

Embodiments of the disclosure provide apparatus, methods and computerprograms for determining a fault in a gas heater channel. It should beappreciated that the present embodiments can be implemented in numerousways, e.g., a process, or an apparatus, or a system, or a piece ofhardware, or a method, or a computer-readable medium. Severalembodiments are described below.

In one embodiment, a system for identifying a heater element of a gasheater channel is described. The gas heater channel includes two heaterelements. The system includes a voltage measurement device and a currentmeasurement device. The voltage measurement device is connected inparallel to each heater element of the gas heater channel and thecurrent measurement device is connected in series to the gas heaterchannel. Such connections of the measurement devices facilitateidentification of a heater element that is inoperational, e.g., is open,is malfunctioning, is broken, etc. A processor receives the voltage andcurrent that are measured by the measurement devices and calculates ameasured parallel resistance. The processor determines whether themeasured parallel resistance is similar to a first ideal parallelresistance of the gas heater channel or a second ideal parallelresistance of the gas heater channel. The first ideal parallelresistance is calculated using an assumption that the first heaterelement is inoperational and the second ideal parallel resistance iscalculated using an assumption that the second heater element isinoperational. Upon determining that the measured parallel resistance issimilar to the first ideal parallel resistance, the processor determinesthat the first gas heater element is inoperational and upon determiningthat the measured parallel resistance is similar to the second idealparallel resistance, the processor determines that the second gas heaterelement is inoperational.

In an embodiment, a method for determining a fault in a gas heaterchannel is described. The method includes receiving from one or moresensors measured parameters associated with a plurality of heaterelements of the gas heater channel. The gas heater channel transfers oneor more gases from a gas supply to a plasma chamber. The method furtherincludes calculating a measured parallel resistance of the plurality ofheater elements from the measured parameters, comparing the measuredparallel resistance to an ideal parallel resistance of the heaterelements of the gas heater channel, and determining based on thecomparison that a portion of the gas heater channel is inoperational.The method includes selecting an identity of one of the heater elementsfrom a correspondence between a plurality of identities of the heaterelements and the measured parallel resistance. The selection of theidentity facilitates identification of the portion of the gas heaterchannel having the fault.

In one embodiment, a method for determining a fault in a gas heaterchannel is described. The method includes receiving from one or moresensors measured parameters associated with a first plurality of heaterelements of the gas heater channel. The gas heater channel transfers oneor more gases from a gas supply to a plasma chamber. The method furtherincludes calculating a measured parallel resistance of the firstplurality of heater elements from the measured parameters associatedwith the first plurality of heater elements, comparing the measuredparallel resistance of the first plurality of heater elements to anideal parallel resistance of the first plurality of heater elements ofthe gas heater channel, and determining based on the comparison that thefirst plurality of heater elements is operational. The method alsoincludes receiving from the one or more sensors measured parametersassociated with a second plurality of heater elements of the gas heaterchannel, calculating a measured parallel resistance of the secondplurality of heater elements from the measured parameters associatedwith the second plurality of heater elements, and comparing the measuredparallel resistance of the second plurality of heater elements to anideal parallel resistance of the second plurality of heater elements ofthe gas heater channel. The method includes determining based on thecomparison that the second plurality of heater elements is inoperationaland selecting an identity of one of the heater elements of the secondplurality of heater elements from a correspondence between a pluralityof identities and the measured parallel resistance of the secondplurality of heater elements. The selection of the one or moreidentities facilitates identification of a portion of the gas heaterchannel having the fault.

In an embodiment, a system for determining a fault in a gas heaterchannel is described. The system includes an alternating current (AC)source configured to generate AC power, a rectifier coupled to the ACsource and configured to convert the AC power into pulsing directcurrent (DC) power, and a transistor. The system further includes a gatedrive coupled to the rectifier and to the transistor and configured todrive the transistor, a channel of heater elements, and a current sensorcoupled to the transistor and to the channel of heater elements andconfigured to sense a current provided to the channel of heaterelements. The current is provided when the transistor is driven. Each ofthe heater elements has a first node and a second node. The systemincludes a voltage sensor coupled to the first node of the heaterelements and the second node of the heater elements and configured tomeasure voltage across each of the heater elements. The system alsoincludes a processor coupled to the voltage sensor and the currentsensor. The processor receives the voltage measured by the voltagesensor and the current sensed by the current sensor, calculates aparallel resistance from the voltage and the current, and determineswhether the calculated parallel resistance is within a pre-determinedthreshold of an ideal parallel resistance of the heater elements. Theprocessor further determines that a portion of the channel isinoperational upon determining that the parallel resistance is notwithin the pre-determined threshold of the ideal parallel resistance.The processor selects an identity of one of the heater elements from acorrespondence between a plurality of identities and the calculatedparallel resistance. The selection of the identity facilitatesidentification of the portion of the channel having the fault.

Some advantages of the herein described systems and methods includeidentifying a heater element that is inoperational by calculating themeasured parallel resistance. A gas heater channel includes tens andsometimes hundreds of heater elements, and if one of those heaterelements becomes inoperational, it is difficult for a user to determinewhich of the heater elements has become inoperational. The systems andmethods described above help identify the heater element that has becomeinoperational.

Other advantages of the herein described systems and methods includeproviding pulsed direct current (DC) power to heater elements of a gasheater channel. The pulsed DC power is more stable compared toalternating current (AC) power and facilitates a stable measurement ofvoltage and current associated with the heater elements. The voltage andcurrent are used to identify a heater element that is inoperational.Without the stability, it is difficult to identify the inoperationalheater element.

Other aspects will become apparent from the following detaileddescription, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments are understood by reference to the following descriptiontaken in conjunction with the accompanying drawings.

FIG. 1A is a diagram of an embodiment of a system for illustrating gasheater channels.

FIG. 1B is a diagram of an embodiment of a system used to determine afault in a gas heater channel.

FIG. 2A is a diagram of an embodiment of a system to illustrate acomplexity of arrangement of gas heater channels.

FIG. 2B is a diagram of an embodiment of system to illustrate thatpulsed direct current (DC) power is provided to gas heater channels.

FIG. 3A is a diagram of an embodiment of a system to illustrate use ofparallel resistance to determine whether there is a fault in a gasheater channel.

FIG. 3B is a diagram of an embodiment of a system for identifying aheater element that is inoperational.

FIG. 3C-1 is a diagram of an embodiment of a system to illustrateidentification of a sub-heater element that is inoperational.

FIG. 3C-2 is a diagram to illustrate identification of a sub-heaterelement or another sub-heater element that is inoperational.

FIG. 4 is a diagram to illustrate that measurements of parameters fromdifferent heater elements within a gas heater channel are used toidentify one or more heater elements of the gas heater channel that areinoperational.

FIG. 5 is a diagram of an embodiment of a system for generating pulsedDC power and for identifying a heater element that is inoperational.

FIG. 6 shows embodiments of a graph to illustrate stability of pulsed DCpower compared to alternating current (AC) power.

FIG. 7 is a diagram of an embodiment of a gas heater channel toillustrate a connection between heater elements of a gas heater channel.

FIG. 8 shows a diagram of an embodiment of a chemical vapor deposition(CVD) system.

FIG. 9 is a diagram of an embodiment of a control module for controllingprocesses within a plasma chamber.

DETAILED DESCRIPTION

The following embodiments describe systems and methods for determining afault in a gas heater channel. It will be apparent that the presentembodiments may be practiced without some or all of these specificdetails. In other instances, well known process operations have not beendescribed in detail in order not to unnecessarily obscure the presentembodiments.

FIG. 1A is a diagram of an embodiment of a system 100 for illustrating anumber of gas heater channels 110, 112A, 112B, 112C, and 112D. Thesystem 100 includes multiple stations 1, 2, 3, and 4, a gas source 108,and a gas line box 114. Examples of a station include a plasma chamber.For example, the station 1 is used to pre-clean a substrate, e.g., asemiconductor wafer, a substrate for a flat panel display, etc. Thestation 2 is used to deposit materials on the substrate, the station 3is used to etch deposited materials from the substrate, and the station4 is used to post-clean the substrate.

The gas source 108 is an enclosure, e.g., a gas tank, etc., that storesone or more process gases, e.g., oxygen-containing gas, afluorine-containing gas, a nitrogen-containing gas, a combination of twoor more thereof, etc. The gas line box 114 includes a flow control unitfor adjusting a flow of the one or more process gases, e.g., a processgas for cleaning, a process gas for deposition, a process gas forsputtering, a process gas for etching, etc. For example, the gas linebox 114 includes a driver, e.g., one or more transistors, etc., thatdrive a flow valve to control a flow rate of the one or more gaseswithin the gas heater channel 110. The driver is connected to a flowcontroller, e.g., a processor and a memory device, etc., and thecontroller provides a signal to the driver to drive the flow valve. Aprocessor, as used herein, refers to a central processing unit (CPU), anapplication specific integrated circuit (ASIC), or a programmable logicdevice (PLD) is used, and these terms are used interchangeably herein.Examples of a memory device include a read-only memory (ROM), a randomaccess memory (RAM), a hard disk, a volatile memory, a non-volatilememory, a redundant array of storage disks, a Flash memory, etc.

In an embodiment, the flow rate is controlled by a motor that isconnected to a valve and the valve is controlled by the flow controllervia the motor and a driver, e.g., one or more transistors, etc., of themotor.

A flow splitter is connected to the gas heater channel 110 to split thegas heater channel 110 into multiple gas heater channels 112A thru 112D.The gas heater channel 112A supplies the one or more process gases tothe station 1, the gas heater channel 112B supplies the one or moreprocess gases to the station 2, the gas heater channel 112C supplies theone or more process gases to the station 3, and the gas heater channel112D supplies the one or more process gases to the station 4.

It should be noted that although four stations are illustrated in FIG.1A, in an embodiment, any other number of stations are connected to thegas heater channel 110 via the same number of gas heater channels. Forexample, the gas heater channel 110 is split into three gas heaterchannels to supply the one or more process gases to the stations 1, 2,and 3. In this example, the system 100 does not include the station 4.

Moreover, it should further be noted that although one gas source 108 isillustrated in FIG. 1A, in one embodiment, more than one gas source isused to supply process gases to one or more of the stations 1 thru 4.For example, the other gas source supplies a process gas to the stations1 and 2 and not to the stations 3 and 4.

In one embodiment, a flow rate of flow of the one or more process gasesflowing within each of the gas heater channels 112A thru 112D iscontrolled separately. For example, a flow valve within the gas heaterchannel 112A is controlled by the flow controller in a manner describedabove to increase or decrease a flow rate of the one or more processgases flowing via the gas heater channel 112A and a flow valve withinthe gas heater channel 112B is controlled by the flow controller in amanner described above to adjust a flow rate of the one or more processgases flowing via the gas heater channel 112B.

FIG. 1B is a diagram of an embodiment of a system 118 used to determinea fault in a combination gas heater channel, which is a combination ofthe gas heater channel 110 and a gas heater channel 120. The gas heaterchannel 120 is an example of any of the gas heater channels 112A thru112D (FIG. 1A).

The system 118 includes the gas line box 114, the gas heater channel120, a plasma chamber 124, one or more parameter measurement device(s)126, an impedance matching circuit (IMC), one or more radio frequency(RF) generators, a host controller, and a display device 122. Examplesof the RF generators include a 400 kilohertz (kHz) RF generator, a 2megahertz (MHz) RF generator, a 27 MHz RF generator, and a 60 MHz RFgenerator. The host controller is connected to the display device 122via a bus. Examples of the display device 122 include a cathode ray tube(CRT) display device, a plasma display device, a light emitting diode(LED) display device, a liquid crystal display (LCD) device, etc. Theflow controller, mentioned above, is an example of the host controller.

An example of the parameter measurement device(s) 126 includes avoltmeter and an ammeter. Another example of the parameter measurementdevice(s) includes an ohmmeter.

The plasma chamber 124 includes an upper electrode (UE) and a lowerelectrode (LE), on which a substrate S is placed for processing usingthe one or more process gases. Each of the upper electrode and the lowerelectrode is made of a metal, e.g., aluminum, alloy of aluminum, etc.The lower electrode is a part of a chuck, e.g., an electrostatic chuck(ESC), etc., within the plasma chamber 124. The lower electrode facesthe upper electrode.

In one embodiment, the upper electrode is grounded.

The host controller provides a signal indicating a corresponding amountof power to be generated by each of the RF generators to each of the RFgenerators. For example, the host controller provides a signal via acable to the 2 MHz RF generator. The signal indicates to a digitalsignal processor (DSP) of the 2 MHz RF generator to control an RF supplywithin the RF generator to generate an RF signal having an amount ofpower indicated in the signal received from the host controller.Moreover, the host controller provides another signal via another cableto the 27 MHz RF generator. The signal indicates to a DSP of the 27 MHzRF generator to generate an RF signal having an amount of powerindicated in the other signal received from the host controller.

The RF generators generate the RF signals and send the RF signals viacorresponding RF cables to the impedance matching circuit. For example,the 2 MHz RF generator generates an RF signal and sends the RF signalvia an RF cable to the impedance matching circuit and the 27 MHz RFgenerator generates an RF signal and sends the RF signal via an RF cableto the impedance matching circuit.

The impedance matching circuit receives the RF signals and filters theRF signals to match an impedance of a load connected to an output of theimpedance matching circuit with that of a source connected to inputs ofthe impedance matching circuit. For example, the impedance matchingcircuit matches an impedance of an RF transmission line 128 thatconnects the impedance matching circuit to the lower electrode LE andthe plasma chamber 124 with that of the RF generators and the RF cablesthat connect the RF generators to the impedance matching circuit. Theimpedance matching circuit matches the impedance of the load with thatof the source to generate a modified RF signal, which is transferred viathe RF transmission line 128 to the lower electrode.

When the one or more process gases are supplied via the gas heaterchannel 120 to a gap 130 between the upper electrode and the lowerelectrode and the modified RF signal is supplied to the lower electrode,plasma is stricken within the gap 130. If plasma is already stricken ata time the one or more process gases are supplied to the gap 130 and themodified RF signal is transferred to the lower electrode, the plasma ismaintained within the gap 130.

Temperature of the one or more process gases in the combination gasheater channel is controlled by heating the one or more process gases.The combination gas heater channel includes heater elements that heatthe one or more process gases. Due to a variety of reasons, e.g.,overheating, excessive electrical current supply, wear and tear, etc.,one or more of the heater elements of the combined gas heater channelbecome inoperational, e.g., malfunction, faulty, do not operate, burnand break, form an open circuit, etc. A gas heater channel includes tensor hundreds or sometimes even thousands of heater elements. It isdifficult for a user to diagnose which of the heater elements isinoperational.

The parameter measurement device(s) 126 are connected to the combinedgas heater channel to measure parameters, e.g., voltage, current, etc.For example, the ammeter measures a current that passes through any ofthe heater elements of the combined gas heater channel and the voltmetermeasures a voltage across each of the heater elements. The current andthe voltage are provided from the parameter measurement device(s) 126 tothe host controller. The host controller calculates parallel resistanceof the heater elements of the combined gas heater channel from thevoltage and the current. From the parallel resistance, one or more ofthe heater elements that are inoperational are identified by the hostcontroller and identities of the one or more of the heater elements aredisplayed on the display device 122 to the user.

It should be noted that in an embodiment, the modified RF signal isprovided to the upper electrode and the lower electrode is groundedinstead of grounding the upper electrode and providing the modified RFsignal to the lower electrode.

FIG. 2A is a diagram of an embodiment of a system 200 to illustrate acomplexity of arrangement of gas heater channels 204A and 204B. Thesystem 200 shows the gas heater channels 204A and 204B. The gas heaterchannel 204A includes heater elements HEA, HEB, HEC, and other heaterelements. Moreover, the gas heater channel 204B includes heater elementsHED, HEE, and other heater elements. The gas heater channel 204A or thegas heater channel 204B is located within the gas line box 114 (FIG. 1A)or outside the gas line box 114.

A gas line 206A is located within the gas heater channel 204A andanother gas line 206B is located within the heater channel 204B. The gasline 206A delivers one or more process gases to one or more stations andthe gas line 206B delivers one or more process gases to one or morestations.

Each heater element is connected to another heater element via aconnector. For example, the heater element HEA is connected to theheater element HEB via a connector C1.

Each gas heater channel 204A and 204B includes a large number of heaterelements. When a device is connected in series to an end of the gasheater channel 204A to determine whether the gas heater channel 204A isinoperational, if one or more of the heater elements of the gas heaterchannel 204A are inoperational, the device does not measure any current.However, when no current is measured using the device, it is difficultto determine which of the heater elements of the gas heater channel 204Aare inoperational.

FIG. 2B is a diagram of an embodiment of system 220 to illustrate thatpulsed direct current (DC) power is provided to gas heater channels 210Aand 210B. The system 220 includes an alternating current (AC) powersource 212, a rectifier 218, and the channels 210A and 210B.

The gas heater channel 210A includes resistors R1, R2, R3, and R4, whichare connected in series with each other. Moreover, the gas heaterchannel 210B includes resistors R5, R6, R7, and R8, which are connectedin series with each other.

In an embodiment, each gas heater channel 210A and 210B includes anyother number of resistors than that illustrated using FIG. 2B. Forexample, the gas heater channel 210A includes 20 resistors connected inseries and the gas heater channel 210B includes 40 resistors in series.

The AC power source 212 generates AC power, e.g., sinusoidal power,power that oscillates peak-to-peak and while oscillating becomes zero,etc., and provides the AC power to the rectifier 218. The rectifier 218converts the AC power into pulsed DC power, which is further describedbelow. The rectifier 218 provides a portion of the pulsed DC power via apath 216A, e.g., a wire connection, etc., to the gas heater channel 210Aand provides the remaining portion of the pulsed DC power via a path216B to the gas heater channel 210B. When the portion of the pulsed DCpower is supplied to the gas heater channel 210A, the gas heater channel210A operates at a temperature tempt. For example, temperature of one ormore process gases within a gas line within the gas heater channel 210Ais temp1. Similarly, when the portion of the pulsed DC power is suppliedto the gas heater channel 210B, the gas heater channel 210B operates ata temperature temp2.

FIG. 3A is a diagram of an embodiment of a system 300 to illustrate useof parallel resistance to determine whether there is a fault in a gasheater channel 310. The gas heater channel 310 is an example of any ofthe gas heater channels 110, 112A, 112B, 112C, 112D (FIG. 1A), and anyother gas heater channel described herein. The system 300 includes thegas heater channel 310, an ammeter A, a voltmeter V, and the hostcontroller. The gas heater channel 310 includes heater elements HE1,HE2, and HE3. The heater elements HE1, HE2, and HE3 are connected inseries in the gas heater channel 310. For example, the heater elementHE1 is connected via a connector to the path 216A and is connected via aconnector to the heater element HE2, the heater element HE2 is connectedvia a connector to the heater element HE3, and the heater element HE3 isgrounded via a connector. As another example, the heater element HE1includes the resistor R1 (FIG. 2B), the heater element HE2 includes theresistor R2 (FIG. 2B), and the heater element HE3 includes the resistorR3 (FIG. 2B), which is grounded.

In one embodiment, the gas heater channel 310 includes any other numberof heater elements, e.g., two, ten, twenty, forty, sixty, hundred, twohundred, in tens, in hundreds, etc., and the heater elements areconnected in series.

The voltmeter V is connected in parallel to a node N1 of each of theheater elements HE1, HE2, and HE3 and to a node N2 of each of the heaterelements H1, H2, and H3. Similarly, the ammeter A is connected in serieswith the node N1 of any of the heater elements HE1, HE2, and HE3. In oneembodiment, instead of the node N1, the ammeter A is connected in serieswith the node N2 of any of the heater elements HE1, HE2, and HE3. Thevoltmeter V is connected to the nodes N1 and N2 of the heater elementsHE1, HE2, and HE3 by the user and the ammeter A is connected to the nodeN1 of any of the heater elements HE1, HE2, and HE3 by the user.

An ideal parallel resistance IPR of the gas heater channel 310 iscalculated by the host controller. For example, the ideal parallelresistance IPR is calculated as:IPR=1/{(1/IR1)+(1/IR2)+(1/IR3)}  (1),where IR1 is an ideal resistance of the heater element HE1, IR2 is anideal resistance of the heater element HE2, and IR3 is an idealresistance of the heater element HE3. The resistances IR1, IR2, and IR3are accessed by the host controller from a specification database, e.g.,specification file, etc., which is stored in the memory device of thehost controller or is accessed via a computer network, e.g., local areanetwork, wide area network, etc., by a host computer that includes thehost controller. As another example, when the gas heater channel 310 isinitially installed or serviced in a plasma system to heat one or moreprocess gases, the voltmeter V measures a voltage between the nodes N1and N2, and the ammeter A measures a current that passes through any ofthe heater elements HE1, HE2, and HE3. For example, the ammeter Ameasures the current at the node N1 of the heater element HE1 or theheater element HE2 or the heater element HE3. The current and thevoltage measured are provided to the host controller, which calculates acommissioned resistance, e.g., the ideal parallel resistance IPR, etc.,from the current and the voltage. For example, the host controllercalculates the commissioned resistance as a ratio of the voltage andcurrent.

During operation of the gas heater channel 310 in a plasma system, e.g.,a period of time after the initial installation or service, a period oftime after the gas heater channel 310 is used within the plasma system,after wear and tear of the gas heater channel 310, etc., the voltmeter Vmeasures a voltage V1 across the nodes N1 and N2 of the heater elementsHE1, HE2, and HE3 and the ammeter A measures a current I1 at the node N1of any of the heater elements HE1, HE2, and HE3. The current I1 is acurrent that flows through any or all of the heater elements HE1, HE2,and HE3. The current I1 is provided by the ammeter A to the hostcontroller and the voltage V1 is provided by the voltmeter V to the hostcontroller.

The host controller calculates a measured parallel resistance MPR fromthe current I1 and the voltage V1. For example, the host controllercalculates the measured parallel resistance to be V141, which is a ratioof V1 and I1. The host controller compares the measured parallelresistance MPR with the ideal parallel resistance IPR to determinewhether the measured parallel resistance MPR is within a predeterminedthreshold THRHOLD, e.g., same as, within a pre-determined range from,etc., of the ideal parallel resistance IPR. Upon determining that themeasured parallel resistance MPR is within the predetermined thresholdTHRHOLD of the ideal parallel resistance IPR, the host controllerdetermines that the gas heater channel 310 is operational, e.g., all theheater elements HE1, HE2, and HE3 are operational, etc. On the otherhand, upon determining that the measured parallel resistance MPR is notwithin the predetermined threshold THRHOLD of the ideal parallelresistance IPR, the host controller determines that the gas heaterchannel 310 is inoperational, e.g., a portion of the gas heater channel310 is inoperational, etc. For example, the heater element HE1 or theheater element HE2, or the heater element HE3, or a connector betweenthe heater element HE1 and the heater element HE2, or a connectorbetween the heater element HE2 and the heater element HE3, or aconnector coupled between the heater element HE1 and the path 216A (FIG.2B), or a connector coupled to the heater element HE3 to ground theheater element HE3, or a combination of two or more thereof, etc., isinoperational.

In one embodiment, a heater element is inoperational when a resistor ofthe heater element is inoperational. In an embodiment, a connector isinoperational when a connection medium, which is described below, of theconnector is inoperational.

It should be noted that when the voltmeter V is connected to the nodesN1 and N2 of the heater elements HE1, HE2, and HE3, the heater elementHE1 is in series with the heater element HE2, which is in series withthe heater element HE3. The connection of the voltmeter V facilitatescalculation of the measured parallel resistance MPR. Similarly, when theammeter A is connected to the node N1 of any of the heater elements HE1,HE2, and HE3, the heater elements HE1, HE2, and HE3 are connected inseries with each other. The connection of the ammeter A facilitatescalculation of the measured parallel resistance MPR.

In one embodiment, the heater element HE1 has a different resistancethan that of the heater element HE2, and the heater element HE2 has adifferent resistance than each of the heater elements HE1 and HE3. Forexample, a resistor of the heater element HE1 is of a different lengththan a length of resistor of a resistor of the heater element HE2 and/ora cross-sectional area of the resistor of the heater element HE1 isdifferent than a cross-sectional area of the resistor of the heaterelement HE2.

FIG. 3B is a diagram of an embodiment of a system 320 for identifyingthe heater element HE1, HE2, or HE3 that is inoperational. The memorydevice of the host controller stores a database 306, e.g., acorrespondence, a mapping, an association, links, etc., between anidentity of a heater element that is inoperational and a value of themeasured parallel resistance MPR. For example, the database 306 includesa mapping between an identity ID1 of the heater element HE1 and a valueIPR1 of the ideal parallel resistance IPR. Moreover, the database 306includes a mapping between an identity ID2 of the heater element HE2 anda value IPR2 of the ideal parallel resistance IPR and includes a mappingbetween an identity ID3 of the heater element HE3 and a value IPR3 ofthe ideal parallel resistance IPR.

The ideal parallel resistance IPR is calculated to be IPR1 by the hostcontroller when the ideal resistance IR1 is not applied in the equation(1) by the host controller to calculate the ideal parallel resistanceIPR. Similarly, the ideal parallel resistance IPR is calculated to beIPR2 when the ideal resistance IR2 is not applied in the equation (1) bythe host controller to calculate the ideal parallel resistance IPR andthe ideal parallel resistance IPR is calculated to be IPR3 when theideal resistance IR3 is not applied in the equation (1) by the hostcontroller to calculate the ideal parallel resistance IPR. The idealparallel resistances IPR1, IPR2, and IPR3 are stored in the database 306by the host controller.

In one embodiment, the ideal parallel resistance IPR1 is calculated whenthe voltmeter V is connected to the node N1 of the heater elements HE2and HE3 and not to the node N1 of the heater element HE1, and isconnected to the node N2 of the heater elements HE2 and HE3 and not tothe node N2 of the heater element HE1, and the ammeter A is connected tothe node N1 of any of the heater elements HE2 and HE3 and not of theheater element HE1. Moreover, the ideal parallel resistance IPR2 iscalculated when the voltmeter V is connected to the node N1 of theheater elements HE1 and HE3 and not to the node N1 of the heater elementHE2, and is calculated when the voltmeter V is connected to the node N2of the heater elements HE1 and HE3 and not to the node N2 of the heaterelement HE2, and the ammeter A is connected to the node N1 of any of theheater elements HE1 and HE3 and not of the heater element HE2. Also, theideal parallel resistance IPR3 is calculated when the voltmeter V isconnected to the node N1 of the heater elements HE1 and HE2 and not tothe node N1 of the heater element HE3, and is connected to the node N2of the heater elements HE1 and HE2 and not to the node N2 of the heaterelement HE3, and the ammeter A is connected to the node N1 of any of theheater elements HE1 and HE2 and not of the heater element HE3.

The host controller determines whether the measured parallel resistanceMPR has a value that is within a pre-determined threshold th, e.g., sameas, within a pre-determined range from, etc., of the value IPR1. Upondetermining that the measured parallel resistance MPR has a value thatis within the pre-determined threshold th of the value IPR1, the hostcontroller determines that the heater element HE1 is inoperational andaccesses the identity ID1 from the database 306 to display via thedisplay device 122 to the user. It should be noted that when theidentity ID1 is displayed, the heater element HE1 and/or a connectorcoupled to the heater element HE1 is inoperational.

On the other hand, upon determining that the measured parallelresistance MPR has a value that is not within the pre-determinedthreshold th of the value IPR1, the host controller determines whetherthe measured parallel resistance MPR has a value that is within thepre-determined threshold th of the value IPR2. Upon determining that themeasured parallel resistance MPR has a value that is within thepre-determined threshold th of the value IPR2, the host controllerdetermines that the heater element HE2 is inoperational and accesses theidentity ID2 from the database 306 for display via the display device122 to the user. It should be noted that when the identity ID2 isdisplayed, the heater element HE2 and/or a connector coupled to theheater element HE2 is inoperational.

Upon determining that the measured parallel resistance MPR has a valuethat is not within the pre-determined threshold th of the value IPR2,the host controller determines whether the measured parallel resistanceMPR has a value that is within the pre-determined threshold th of thevalue IPR3. Upon determining that the measured parallel resistance MPRhas a value that is within the pre-determined threshold th of the valueIPR3, the host controller determines that the heater element HE3 isinoperational and accesses the identity ID3 from the database 306 todisplay via the display device 122 to the user. It should be noted thatwhen the identity ID3 is displayed, the heater element HE3 and/or aconnector coupled to the heater element HE3 is inoperational.

It should be noted that in an embodiment, an identity of a heaterelement is provided to the user in the form of a sound via audioequipment, e.g., amplifier and speaker, etc., instead of or in additionto using the display device 122.

In one embodiment, an identity of a heater element is transferred viathe computer network to another host computer to display to the userand/or to provide to the user in the form of sound.

FIG. 3C-1 is a diagram of an embodiment of a system 330 to illustrateidentification of a sub-heater element HE21 or HE22 that are portions ofa combined heater element, e.g., the heater element HE2, etc. Forexample, the combined heater element includes two sub-heater elementsHE21 and HE22 instead of being one heater element. As another example,the combined heater element includes two resistors R21 and R22 insteadof including one resistor R2. The sub-heater element H21 is connected tothe heater element HE1 via a connector and the sub-heater element H22 isconnected to the heater element HE3 via a connector.

In one embodiment, the sub-heater elements HE21 and HE22 are connectedwith each other via a connector.

The sub-heater elements HE21 and HE22 are connected in series with eachother and to the heater element HE1 and to the heater element HE3 whenimplemented within a channel 311, which is an example of the channel110, or the channel 112A, or the channel 112B, or the channel 112C, orthe channel 112D (FIG. 1A). For example, the combined heater element isconnected via a connector to the heater element HE1 and is connected viaa connector to the heater element HE3.

The ideal parallel resistance IPR of the channel 311 is calculated inone of various manners described above of calculating the ideal parallelresistance IPR of the channel 310 except that IR2 is a total resistanceof the sub-heater elements HE21 and HE22 instead of being the resistanceof the heater element HE2. Moreover, the measured parallel resistanceMPR of the channel 311 is calculated in a manner described above ofcalculating the measured parallel resistance MPR of the channel 310.

The host controller compares the measured parallel resistance MPR of thechannel 311 with the ideal parallel resistance IPR of the channel 311.Upon determining that the measured parallel resistance MPR of thechannel 311 is within the pre-determined threshold THRHOLD of the idealparallel resistance IPR of the channel 311, the host controllerdetermines that the heater elements of the channel 311 are operational.On the other hand, upon determining that the measured parallelresistance MPR of the channel 311 is not within the pre-determinedthreshold THRHOLD of the ideal parallel resistance IPR of the channel311, the host controller determines that the heater element HE1, or thesub-heater element HE21, or the sub-heater element HE22, or the heaterelement HE3, or a connector between the heater element HE1 and thesub-heater element HE21, or a connector between the sub-heater elementHE21 and the sub-heater element HE22, or a connector between thesub-heater element HE22 and the heater element HE3, or a connectorbetween the path 216A (FIG. 2B) and the heater element HE1, or aconnector coupled to the heater element HE3 to ground the heater elementHE3, or a combination of two or more thereof, etc., is inoperational.

In one embodiment, the sub-heater element HE21 has a differentresistance than that of the sub-heater element HE22. For example, aresistor of the sub-heater element HE21 is of a different length than alength of a resistor of the sub-heater element HE22 and/or across-sectional area of the resistor of the sub-heater element HE21 isdifferent than a cross-sectional area of the resistor of the sub-heaterelement HE22.

FIG. 3C-2 is a diagram to illustrate identification of the sub-heaterelement HE21 or the sub-heater element HE22 that is inoperational. Thevoltmeter V is connected by the user to a node N21 and a node N22 of asub-channel that includes the sub-heater elements HE21 and HE22.Moreover, the ammeter A is connected to the node N21 of any of thesub-heater elements HE21 and HE22 by the user.

An ideal parallel resistance IPSR of the sub-heater elements HE21 andHE22 is calculated by the host controller. For example, the idealparallel resistance IPSR is calculated as:IPSR=1/{(1/IR21)+(1/IR22)}  (2),

where IR21 is an ideal resistance of the sub-heater element HE21 andIR22 is an ideal resistance of the sub-heater element HE22. The idealresistances IR21 and IR22 are accessed by the host controller from aspecification database, e.g., specification file, etc., which is storedin the memory device of the host controller or is accessed via thecomputer network by the host computer. As another example, when the gasheater channel 311 (FIG. 3C-1) is initially installed or serviced in aplasma system to heat one or more process gases, the voltmeter Vmeasures a voltage between the nodes N21 and N22, and the ammeter Ameasures a current that passes through any of the sub-heater elementsHE21 and HE22. For example, the ammeter A measures the current at thenode N21 of any of the sub-heater elements HE21 and HE22. The currentand the voltage measured is provided to the host controller, whichcalculates a commissioned resistance, e.g., the ideal parallelresistance IPSR, etc., from the current and the voltage. For example,the host controller calculates the commissioned resistance as a ratio ofthe voltage and current.

The ideal parallel resistance IPSR is calculated to be IPSR21 by thehost controller when the ideal resistance IR21 is not applied in theequation (2) by the host controller. Similarly, the ideal parallelresistance IPSR is calculated to be IPSR22 when the ideal resistanceIR22 is not applied in the equation (2) by the host controller. Theideal parallel resistances IPSR21 and IPSR22 are stored in a database340 by the host controller. The database 340 is stored in the memorydevice of the host controller.

In one embodiment, the ideal parallel resistance IPSR21 is calculatedwhen the voltmeter V is connected to the node N21 of the sub-heaterelement HE22 and not to the node N21 of the sub-heater element HE21, andis connected to the node N22 of the sub-heater element HE22 and not tothe node N22 of the sub-heater element HE21, and the ammeter A isconnected to the node N21 of the sub-heater element HE22 and not to thenode N21 of the sub-heater element HE21. Moreover, the ideal parallelresistance IPSR22 is calculated when the voltmeter V is connected to thenode N21 of the sub-heater element HE21 and not to the node N21 of thesub-heater element HE22, and is connected to the node N22 of thesub-heater element HE21 and not to the node N22 of the sub-heaterelement HE22, and the ammeter A is connected to the node N21 of thesub-heater element HE21 and not to the node N21 of the sub-heaterelement HE22.

During operation of the gas heater channel 311 in a plasma system, e.g.,a period of time after the initial installation or service of the gasheater channel 311, a period of time after the gas heater channel 311 isused within the plasma system, after wear and tear of the gas heaterchannel 311, etc., the voltmeter V measures a voltage V2 across thenodes N21 and N22 of the sub-heater elements HE21 and HE22 and theammeter A measures a current I2 at the node N21 of any of the sub-heaterelements HE21 and HE22. The current I2 is a current that flows throughany of the sub-heater elements HE21 and HE22. The current I2 is providedby the ammeter A to the host controller and the voltage V2 is providedby the voltmeter V to the host controller. The host controllercalculates the measured parallel resistance MPSR as a ratio of thevoltage V2 and the current I2.

The database 340 includes an identity of a sub-heater element that isinoperational and a value of the measured parallel resistance MPSR. Forexample, the database 340 includes a mapping between an identity ID21 ofthe sub-heater element HE21 and the value IPSR21 of the ideal parallelresistance IPSR. Moreover, the database 340 includes a mapping betweenan identity ID22 of the sub-heater element HE22 and a value IPSR22 ofthe ideal parallel resistance IPSR.

The host controller determines whether the measured parallel resistanceMPSR has a value that is within a pre-determined range rnge, e.g., sameas, within a pre-determined limit from, etc., of the value IPSR21. Upondetermining that the measured parallel resistance MPSR has a value thatis within the pre-determined range rnge of the value IPSR21, the hostcontroller determines that the sub-heater element HE21 is inoperationaland accesses the identity ID21 from the database 340 to indicate via thedisplay device 122 (FIG. 1B) to the user that the sub-heater elementHE21 is inoperational. It should be noted that when the identity ID21 isdisplayed, the sub-heater element HE21 and/or a connector coupled to thesub-heater element HE21 is inoperational.

On the other hand, upon determining that the measured parallelresistance MPSR has a value that is not within the pre-determined rangernge of the value IPSR21, the host controller determines whether themeasured parallel resistance MPSR has a value that is within thepre-determined range rnge of the value IPSR22. Upon determining that themeasured parallel resistance MPSR has a value that is within thepre-determined range rnge of the value IPSR22, the host controllerdetermines that the sub-heater element HE22 is inoperational andaccesses the identity ID22 from the database 340 for display via thedisplay device 122 to the user. It should be noted that when theidentity ID22 is displayed, the sub-heater element HE22 and/or aconnector coupled to the sub-heater element HE22 is inoperational.

It should be noted that in an embodiment, an identity of a sub-heaterelement is provided to the user in the form of a sound via the audioequipment instead of or in addition to using the display device 122.

It should further be noted that when the voltmeter V is connected to thenodes N21 and N22, the sub-heater element HE21 is in series with theheater element HE22. The connection of the voltmeter V facilitatescalculation of the measured parallel resistance MPSR. Similarly, whenthe ammeter A is connected to the node N21, the sub-heater element HE21is in series with the sub-heater element HE22. The connection of theammeter A facilitates calculation of the measured parallel resistanceMPSR.

In one embodiment, an identity of a sub-heater element is transferredvia the computer network to another host computer to display to the userand/or to provide to the user in the form of sound.

FIG. 4 is a diagram to illustrate that measurements of parameters fromdifferent heater elements within a gas heater channel 410 are used toidentify one or more heater elements of the gas heater channel 410 thatare operational. The gas heater channel 410 includes the heater elementHE1, the heater element HE2, the heater element HE3, a heater elementHE4, and a heater element HE5. The heater element HE1 is connected inseries with the heater element HE2, the heater element HE2 is connectedin series with the heater element 3, the heater element 3 is connectedin series with the heater element 4, and the heater element HE4 isconnected in series with the heater element HE5. The heater element HE5is grounded.

In one embodiment, the gas heater channel 410 includes any other numberof heater elements, e.g., ten, twenty, in tens, in hundreds, etc.

The user connects the ammeter A to the node N1 of the heater element HE1and connects the voltmeter V to the nodes N1 and N2 of the heaterelements HE1, HE2, and HE3. As explained above with reference to FIGS.3A and 3B, the host controller then determines whether a portion, e.g.,a segment, etc., of the gas heater channel 410 that includes the heaterelements HE1, HE2, and HE3 is operational. Upon determining that theportion of the gas heater channel 410 that includes the heater elementsHE1, HE2, and HE3 is inoperational, the heater element HE1, or theheater element HE2, or the heater element HE3 is identified by the hostcontroller.

On the other hand, upon determining that the portion that includes theheater elements HE1, HE2, and HE3 is operational, the user removes theconnection of the voltmeter V from the nodes N1 and N2 of each of theheater elements HE1, HE2, and HE3. Also, the user removes the connectionof the ammeter A from the node N1 of the heater element HE1. The userthen connects the voltmeter V to the nodes N1 and N2 of the heaterelements HE4 and HE5, and connects the ammeter A to the node N1 of theheater element HE4 or of HE5.

Then, in a manner similar to that explained above with reference toFIGS. 3A and 3B, the host controller then determines whether a portion,e.g., a segment, etc., of the gas heater channel 410 that includes theheater elements HE4 and HE5 is operational. Upon determining that theportion of the gas heater channel 410 that includes the heater elementsHE4 and HE5 is inoperational, the heater element HE4 or the heaterelement HE5 is identified by the host controller.

FIG. 5 is a diagram of an embodiment of a system 500 for generatingpulsed DC power and for identifying a heater element that isinoperational. The system 500 includes a rectifier 514, a voltage sensor520, a filter 522, a processor 524, gate drives 518, transistors 516A,516B, and 516C, current sensors 520A, 520B, and 520C, and gas heaterchannels 510A, 510B, and 510C. An example of each of the gate drives 518includes a transistor.

The rectifier 514 is an example of the rectifier 218 (FIG. 2B), thevoltage sensor 520 is an example of the voltmeter V, and the processor524 is an example of the processor of the host controller. Also, any ofthe current sensors 520A, 520B, and 520C is an example of the ammeter A.Moreover, the gas heater channel 510A is an example of the gas heaterchannel 110 or of the gas heater channel 112A or of the gas heaterchannel 112B or of the gas heater channel 112C or of the gas heaterchannel 112D. Also, the gas heater channel 510B is an example of the gasheater channel 110 or of the gas heater channel 112A or of the gasheater channel 112B or of the gas heater channel 112C or of the gasheater channel 112D. Moreover, the gas heater channel 510C is an exampleof the gas heater channel 110 or of the gas heater channel 112A or ofthe gas heater channel 112B or of the gas heater channel 112C or of thegas heater channel 112D.

The AC power source 212 (FIG. 2B) supplies AC power to the rectifier514. The rectifier 514 rectifies, e.g., converts, etc., the AC powerinto a pulsed DC power 504. A first portion of the pulsed DC power 504is supplied via an ND1 bus 530A and a bus 532A to the gas heater channel510A, a second portion of the pulsed DC power 504 is supplied via theND1 bus 530A and a bus 532B to the gas heater channel 510B, and a thirdportion of the pulsed DC power 504 is supplied via the ND1 bus and a bus532C to the gas heater channel 510C.

It should be noted that the filter 522 filters the pulsed DC power togenerate smooth pulsed DC power, which is provided to the processor 524.The processor 524 sends control signals to the gate drives 518. One ofthe gate drives 518 generates a power signal upon receiving one of thecontrol signals and provides the power signal via a gate 534A to thetransistor 516A. Similarly, another one of the gate drives 518 generatesa power signal upon receiving another one of the control signals andprovides the power signal via a gate 534B to the transistor 516B. Also,yet another one of the gate drives 518 generates a power signal uponreceiving another one of the control signals and provides the powersignal via a gate 534C to the transistor 516C.

Upon receiving the power signal via the gate 534A, the transistor 516Ais activated and the transistor 516A transfers the portion of the pulsedDC power received via the bus 532A and the current sensor 520A to thegas heater channel 510A, which includes heater elements 540A, 540B,540C, and 540D. The heater elements 540A, 540B, 540C, and 540D generateheat upon receiving the portion of the pulsed DC power 504 to heat oneor more process gases within a gas line within the gas heater channel510A.

Similarly, upon receiving the power signal via the gate 534B, thetransistor 516B is turned on and transfers the portion of the pulsed DCpower received via the bus 532B and the current sensor 520B to one ormore heater elements of the gas heater channel 510B. The one or moreheater elements of the gas heater channel 510B generate heat uponreceiving the portion of the pulsed DC power 504 to heat one or moreprocess gases within a gas line within the gas heater channel 510B.

Also, upon receiving the power signal via the gate 534C, the transistor516C is turned on and transfers the portion of the pulsed DC powerreceived via the bus 532C and the current sensor 520C to one or moreheater elements of the gas heater channel 510C. The one or more heaterelements of the gas heater channel 516C generate heat upon receiving theportion of the pulsed DC power 504 to heat one or more process gaseswithin a gas line within the gas heater channel 510C.

The heater elements 540A, 540B, 540C, and 540C are connected in serieswith each other. For example, an output of the heater element 540A isconnected to an input of the heater element 540B, an output of theheater element 540B is connected to an input of the heater element 540C,and an output of the heater element 540C is connected to an input of theheater element 540D.

It should be noted that although four heater elements are illustrated inthe gas heater channel 510A, in an embodiment, the gas heater channel510A includes any other number of heater elements.

The current sensor 520A measures an amount of current that passes viathe transistor 516A to each of the heater elements 540A, 540B, 540C, and540D of the gas heater channel 510A. Similarly, the current sensor 520Bmeasures an amount of current that passes via the transistor 516B to theone or more heater elements of the gas heater channel 510B and thecurrent sensor 520C measures an amount of current that passes via thetransistor 516C to the one or more heater elements of the gas heaterchannel 510C.

Moreover, the voltage sensor 520 measures an amount of voltage betweennodes ND1 and ND2 and the node ND2 is located on an ND2 bus 530B. Thevoltage is voltage between node ND1 and node ND2 of each of the heaterelements 540A, 540B, 540C, and 540D.

By converting the AC power into the pulsed DC power 504, the voltagesensor 520 measures the voltage in a reliable manner and the currentsensors 520A, 520B, and 520C measure the currents reliably. Moreover,the voltage measured for the gas heater channel 510A is sent from thevoltage sensor 520 to the processor 524 and the current measured for thegas heater channel 510A is sent from the current sensor 520A to theprocessor 524. The voltage and current then are used by the processor524 to identify one of the heater elements 540A, 540B, 540C, and 540Dthat is inoperational in a manner similar to that described above.

FIG. 6 shows embodiments of a graph 600 to illustrate stability ofpulsed DC power compared to AC power. The graph 600 plots pulsed DCvoltage 612, DC pulsed power 610, and 3-phase AC power 614 versus timet. The pulsed DC power 610 is generated from the pulsed DC voltage 612.The 3-phase AC power 614 is generated by the AC power source 212 (FIG.2B). A rectifier generates the DC pulsed power 610 from the 3-phase ACpower 614.

It should be noted that the 3-phase AC power 614 oscillates and becomeszero periodically. The oscillation and cycling through zero makes use ofthe 3-phase AC power 614 unstable and less reliable in measuring theparameters compared to use of the DC pulsed power 610 in measuring theparameters. The DC pulsed power 610 does not become zero and is morereliable than the 3-phase AC power 614. The user of DC pulsed power 610provides continuous power delivery, e.g., at all instances of time,etc., to heater elements of a gas heater channel and the continuouspower delivery makes the measurement of the parameters more reliablecompared to intermittent power delivery of the 3-phase AC power 614.Moreover, the DC pulsed power 610 has smaller size energy packets thanthat of the 3-phase AC power 614 to reduce stress on a heater element towhich the DC pulsed power 610 is provided. Moreover, the DC pulsed power610 has an increased voltage compared to the 3-phase AC power 614. Forthe same amount of power, the increased voltage of the DC pulsed power610 reduces average current passing through a heater element to whichthe DC pulsed power 610 is provided to decrease power lost by the heaterelement. Furthermore, use of the DC pulsed power 610 allows use of afiring order for energizing the heater channels 510A, 510B, and 510C(FIG. 5) to allow for precise energy management. Also, there is no needto use a snap action over temperature switch when the DC pulsed power610 is supplied to the heater channels 510A, 510B, and 510C.

FIG. 7 is a diagram of an embodiment of a gas heater channel 700 toillustrate a connection between heater elements 702A and 702B of a gasheater channel 700. The heater element 702A includes a resistor 704A andthe heater element 702B includes a resistor 704B. The heater elements702A and 702B are connected to each other via a connector 706. Theconnector 706 includes a connection medium 708, e.g., a wire, etc., thatconnects to the resistor 704A at a connection point 710A. Similarly, theconnection medium 708 connects to the resistor 704B at a connectionpoint 710B. The heater elements 702A and 702B generate heat that heatsone or more process gases flowing through a gas line 720.

The heater element 702A includes a tube 712A that encloses and surroundsthe resistor 704A. Similarly, the connector 706 includes a tube 712Bthat encloses and surrounds the connection medium 708. Also, the heaterelement 702B includes a tube 712C that encloses and surrounds theresistor 704C. The tube 712A fits with the tube 712B, which fits withthe tube 712C.

In an embodiment, a tube is made of one or more metals, e.g., aluminum,steel, or a combination thereof, etc.

FIG. 8 shows an exemplary chemical vapor deposition (CVD) system 800. Adeposition of film is implemented in a plasma enhanced chemical vapordeposition (PECVD) system. The PECVD system may take many differentforms. The PECVD system includes one or more plasma chambers or“reactors” (sometimes including multiple stations) that house one ormore wafers and are suitable for wafer processing. Each plasma chamberhouses one or more wafers for processing. The one or more plasmachambers maintain a wafer in a defined position or positions (with orwithout motion within that position, e.g. rotation, vibration, or otheragitation). A wafer undergoing deposition may be transferred from onestation to another during the process. Of course, in one embodiment, thefilm deposition occurs entirely at a single station or any fraction ofthe film is deposited at any number of stations.

While in process, each wafer is held in place by a pedestal, wafer chuckand/or other wafer holding apparatus. For certain operations, theapparatus may include a heater such as a heating plate to heat thewafer. For example, a reactor 802 in FIG. 8 includes a process chamber804, which encloses other components of the reactor and contains plasma.The plasma may be generated by a capacitor type system including ashowerhead 806 working in conjunction with a grounded heater block 808.A high-frequency RF generator 810 and a low-frequency RF generator 814are connected to the showerhead 806 via a matching network 812. Thepower and frequency supplied by the matching network 812 is sufficientto generate plasma from a process gas.

Within the reactor 802, a wafer pedestal 816 supports a substrate 818.The pedestal 816 typically includes a chuck, a fork, or lift pins tohold and transfer the substrate during and between the deposition and/orother plasma processes. Examples of the chuck include an electrostaticchuck and a mechanical chuck. One or more process gases are introducedvia an inlet 824. Multiple source gas lines 826A, 826B, and 826C areconnected to a manifold 830. One or more process gases are premixed ornot. Appropriate valving and mass flow control mechanisms are employedto ensure that the correct process gases are delivered during a process.

Process gases exit the reactor 802 via an outlet 834. A vacuum pump 836(e.g., a one or two stage mechanical dry pump and/or a turbomolecularpump) draws process gases out and maintains a suitably low pressurewithin the reactor by a close loop controlled flow restriction device,such as a throttle valve or a pendulum valve. It is possible to indexwafers after every deposition and/or post-deposition plasma annealtreatment until all the required depositions and treatments arecompleted, or multiple depositions and treatments can be conducted at asingle station before indexing the wafer.

In one embodiment, the inter-electrode gap is illustrated between theshowerhead 806 (powered top electrode), and the pedestal 816 (e.g.,grounded electrode) over which the wafer 818 is placed. As described inmore detail below, bottom electrode or top electrode may be verticallyadjusted to change the gap, so as to set or achieve a desired uniformityprofile during deposition.

FIG. 9 shows a control module 900 for controlling processes within aplasma chamber described above. The control module 900 is an example ofthe host controller. In one embodiment, the control module 900 includessome example components. For instance, the control module 900 includes aprocessor, memory and one or more interfaces. The control module 900 isemployed to control devices in the plasma system based in part on sensedvalues. For example, the control module 900 controls one or more ofvalves 902, filter heaters 904, pumps 906, and other devices 908 basedon sensed values and other control parameters. The control module 900receives the sensed values from, for example, pressure manometers 910,flow meters 912, temperature sensors 914, and/or other sensors 916. Thecontrol module 900 is be employed to control process conditions, e.g.,during precursor delivery and deposition of a film, etc. In oneembodiment, the control module 900 will typically include one or morememory devices and one or more processors.

The control module 900 controls activities associated with implementingthe process conditions. For example, the control module 900 executescomputer programs including sets of instructions for controlling processtiming, delivery system temperature, pressure differentials across thefilters, valve positions, mixture of gases, chamber pressure, chambertemperature, wafer temperature, RF power levels, wafer chuck or pedestalposition, and other parameters of a particular process.

Typically, there will be a user interface associated with the controlmodule 900. The user interface includes a display 918 (e.g. a displayscreen and/or graphical software displays of the apparatus and/orprocess conditions), and user input devices 920 such as pointingdevices, keyboards, touch screens, microphones, etc. The display 918 isan example of the display device 122 (FIG. 1B).

A computer program for controlling implementing of the processconditions can be written in any conventional computer readableprogramming language: for example, assembly language, C, C++, Pascal,Fortran or others. Compiled object code or script is executed by theprocessor to perform the tasks identified in the computer program.

The control module parameters relate to the process conditions such as,for example, filter pressure differentials, process gas composition andflow rates, temperature, pressure, plasma conditions such as RF powerlevels and the low frequency RF frequency, cooling gas pressure, andchamber wall temperature.

The computer program is designed or configured in many different ways.For example, various chamber component subroutines or control objectsare written to control operation of components of the plasma chamber 124(FIG. 1B) to carry out the process conditions. Examples of programs orsections of programs for this purpose include substrate positioningcode, process gas control code, pressure control code, heater controlcode, and plasma control code.

A substrate positioning program includes a program code for controllingchamber components that are used to load a substrate onto a pedestal orchuck and to control spacing between the substrate and other parts ofthe plasma chamber 124 such as a gas inlet and/or target. A process gascontrol program includes a program code for controlling gas compositionand flow rates and optionally for flowing gas into the plasma chamber124 prior to deposition in order to stabilize the pressure in the plasmachamber 124. A filter monitoring program includes a program code thatcompares measured differential(s) to predetermined value(s) and/or codefor switching paths. A pressure control program includes a program codefor controlling pressure in the plasma chamber 124 by regulating, e.g.,a throttle valve in an exhaust system of the plasma chamber 124. Aheater control program includes a program code for controlling a currentto heater elements for heating one or more process gases in a gas line,for heating the substrate, and/or other portions of the system. Forexample, the heater control program controls delivery of a heat transfergas, such as, e.g., helium, etc., to the wafer chuck.

Examples of sensors that may be monitored during a process include, butare not limited to, mass flow control modules, pressure sensors such asthe pressure manometers 910, and thermocouples located in deliverysystem, the pedestal or chuck (e.g. the temperature sensors 914).Appropriately programmed feedback and control algorithms are used withdata from these sensors to maintain desired process conditions. Theforegoing describes implementation of embodiments of the invention in asingle or multi-chamber semiconductor processing tool.

In one embodiment, functions described herein as being performed by acontroller are performed by a processor of the controller.

In an embodiment, functions described herein as being performed by acontroller are performed by multiple controllers, e.g., are distributedbetween multiple controllers.

Embodiments, described herein, may be practiced with various computersystem configurations including hand-held hardware units, microprocessorsystems, microprocessor-based or programmable consumer electronics,minicomputers, mainframe computers and the like. The embodiments,described herein, can also be practiced in distributed computingenvironments where tasks are performed by remote processing hardwareunits that are linked through a computer network.

In some embodiments, a controller is part of a system, which may be partof the above-described examples. The system includes semiconductorprocessing equipment, including a processing tool or tools, chamber orchambers, a platform or platforms for processing, and/or specificprocessing components (a wafer pedestal, a gas flow system, etc.). Thesystem is integrated with electronics for controlling its operationbefore, during, and after processing of a semiconductor wafer orsubstrate. The electronics is referred to as the “controller,” which maycontrol various components or subparts of the system. The controller,depending on processing requirements and/or a type of the system, isprogrammed to control any process disclosed herein, including a deliveryof process gases, temperature settings (e.g., heating and/or cooling),pressure settings, vacuum settings, power settings, RF generatorsettings, RF matching circuit settings, frequency settings, flow ratesettings, fluid delivery settings, positional and operation settings,wafer transfers into and out of a tool and other transfer tools and/orload locks connected to or interfaced with the system.

Broadly speaking, in a variety of embodiments, the controller is definedas electronics having various integrated circuits, logic, memory, and/orsoftware that receive instructions, issue instructions, controloperation, enable cleaning operations, enable endpoint measurements, andthe like. The integrated circuits include chips in the form of firmwarethat store program instructions, digital DSPs, chips defined as ASICs,PLDs, one or more microprocessors, or microcontrollers that executeprogram instructions (e.g., software). The program instructions areinstructions communicated to the controller in the form of variousindividual settings (or program files), defining operational parametersfor carrying out a process on or for a semiconductor wafer. Theoperational parameters are, in some embodiments, a part of a recipedefined by process engineers to accomplish one or more processing stepsduring the fabrication of one or more layers, materials, metals, oxides,silicon, silicon dioxide, surfaces, circuits, and/or dies of a wafer.

The controller, in some embodiments, is a part of or coupled to acomputer that is integrated with, coupled to the system, otherwisenetworked to the system, or a combination thereof. For example, thecontroller is in a “cloud” or all or a part of a fab host computersystem, which allows for remote access for wafer processing. Thecontroller enables remote access to the system to monitor currentprogress of fabrication operations, examines a history of pastfabrication operations, examines trends or performance metrics from aplurality of fabrication operations, to change parameters of currentprocessing, to set processing steps to follow a current processing, orto start a new process.

In some embodiments, a remote computer (e.g. a server) provides processrecipes to the system over a computer network, which includes a localnetwork or the Internet. The remote computer includes a user interfacethat enables entry or programming of parameters and/or settings, whichare then communicated to the system from the remote computer. In someexamples, the controller receives instructions in the form of settingsfor processing a wafer. It should be understood that the settings arespecific to a type of process to be performed on a wafer and a type oftool that the controller interfaces with or controls. Thus as describedabove, the controller is distributed, such as by including one or morediscrete controllers that are networked together and working towards acommon purpose, such as the fulfilling processes described herein. Anexample of a distributed controller for such purposes includes one ormore integrated circuits on a chamber in communication with one or moreintegrated circuits located remotely (such as at a platform level or aspart of a remote computer) that combine to control a process in achamber.

Without limitation, in various embodiments, the system includes a plasmaetch chamber, a deposition chamber, a spin-rinse chamber, a metalplating chamber, a clean chamber, a bevel edge etch chamber, a physicalvapor deposition (PVD) chamber, a CVD chamber, an atomic layerdeposition (ALD) chamber, an atomic layer etch (ALE) chamber, an ionimplantation chamber, a track chamber, and any other semiconductorprocessing chamber that is associated or used in fabrication and/ormanufacturing of semiconductor wafers.

It is further noted that although the above-described operations aredescribed with reference to a parallel plate plasma chamber, e.g., acapacitively coupled plasma chamber, etc., in some embodiments, theabove-described operations apply to other types of plasma chambers,e.g., a plasma chamber including an inductively coupled plasma (ICP)reactor, a transformer coupled plasma (TCP) reactor, conductor tools,dielectric tools, a plasma chamber including an electron cyclotronresonance (ECR) reactor, etc. For example, the x MHz RF generator, the yMHz RF generator, and the z MHz RF generator are coupled via animpedance matching network to an inductor within the ICP plasma chamber.

As noted above, depending on a process operation to be performed by thetool, the controller communicates with one or more of other toolcircuits or modules, other tool components, cluster tools, other toolinterfaces, adjacent tools, neighboring tools, tools located throughouta factory, a main computer, another controller, or tools used inmaterial transport that bring containers of wafers to and from toollocations and/or load ports in a semiconductor manufacturing factory.

With the above embodiments in mind, it should be understood that some ofthe embodiments employ various computer-implemented operations involvingdata stored in computer systems. These computer-implemented operationsare those that manipulate physic al quantities.

Some of the embodiments also relate to a hardware unit or an apparatusfor performing these operations. The apparatus is specially constructedfor a special purpose computer. When defined as a special purposecomputer, the computer performs other processing, program execution orroutines that are not part of the special purpose, while still beingcapable of operating for the special purpose.

In some embodiments, the operations, described herein, are performed bya computer selectively activated, or are configured by one or morecomputer programs stored in a computer memory, or are obtained over acomputer network. When data is obtained over the computer network, thedata may be processed by other computers on the computer network, e.g.,a cloud of computing resources.

One or more embodiments, described herein, can also be fabricated ascomputer-readable code on a non-transitory computer-readable medium. Thenon-transitory computer-readable medium is any data storage hardwareunit, e.g., a memory device, etc., that stores data, which is thereafterread by a computer system. Examples of the non-transitorycomputer-readable medium include hard drives, network attached storage(NAS), ROM, RAM, compact disc-ROMs (CD-ROMs), CD-recordables (CD-Rs),CD-rewritables (CD-RWs), magnetic tapes and other optical andnon-optical data storage hardware units. In some embodiments, thenon-transitory computer-readable medium includes a computer-readabletangible medium distributed over a network-coupled computer system sothat the computer-readable code is stored and executed in a distributedfashion.

Although some method operations, described above, were presented in aspecific order, it should be understood that in various embodiments,other housekeeping operations are performed in between the methodoperations, or the method operations are adjusted so that they occur atslightly different times, or are distributed in a system which allowsthe occurrence of the method operations at various intervals, or areperformed in a different order than that described above.

It should further be noted that in an embodiment, one or more featuresfrom any embodiment described above are combined with one or morefeatures of any other embodiment without departing from a scopedescribed in various embodiments described in the present disclosure.

Although the foregoing embodiments have been described in some detailfor purposes of clarity of understanding, it will be apparent thatcertain changes and modifications can be practiced within the scope ofappended claims. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the embodiments arenot to be limited to the details given herein, but may be modifiedwithin the scope and equivalents of the appended claims.

The invention claimed is:
 1. A method for determining a fault in a gasheater channel, comprising: receiving from one or more sensors measuredparameters associated with a plurality of heater elements of the gasheater channel, wherein the plurality of heater elements are coupled inseries to form a plurality of series-coupled heater elements, wherein afirst one of the plurality of series-coupled heater elements is coupledvia a connector to a second one of the plurality of series-coupledheater elements, wherein the gas heater channel is configured totransfer one or more gases from a gas supply to a plasma chamber;calculating a measured parallel resistance of the plurality ofseries-coupled heater elements from the measured parameters; comparingthe measured parallel resistance to an ideal parallel resistance of theplurality of series-coupled heater elements of the gas heater channel;determining based on the comparison that a portion of the gas heaterchannel is inoperational, wherein the portion of the gas heater channelincludes the first one of the plurality of the series-coupled heaterelements; and selecting an identity of the first one of the plurality ofseries-coupled heater elements from a correspondence between a pluralityof identities of the plurality of series-coupled heater elements and themeasured parallel resistance, wherein the selection of the identityfacilitates identification of the first one of the plurality ofseries-coupled heater elements having the fault.
 2. The method of claim1, further comprising providing the identity of the first one of theplurality of series-coupled heater elements for display on a displayscreen.
 3. The method of claim 1, further comprising: receivingalternating current (AC) power from an AC power source; converting theAC power into pulsed direct current (DC) power; and providing the pulsedDC power to the plurality of series-coupled heater elements of the gasheater channel for heating a gas supply line and for measuring theparameters using the one or more sensors.
 4. The method of claim 3,wherein the gas supply line is coupled to a plurality of gas supplylines for transferring the one or more gases to the plasma chamber andadditional plasma chambers.
 5. The method of claim 1, wherein the one ormore sensors include a plurality of sensors, wherein the plurality ofsensors includes a voltage sensor and a current sensor.
 6. The method ofclaim 1, further comprising receiving parameters from the one or moresensors to calculate the ideal parallel resistance, wherein the idealparallel resistance is calculated before the measured parallelresistance is calculated.
 7. The method of claim 1, further comprisingdetermining based on the comparison that the measured parallelresistance is not within a pre-determined threshold of the idealparallel resistance, wherein determining that the portion of the gasheater channel is inoperational is performed upon determining that themeasured parallel resistance is not within the pre-determined thresholdof the ideal parallel resistance.
 8. The method of claim 1, furthercomprising: determining whether the measured parallel resistance iswithin a threshold of a first value of the ideal parallel resistance orwithin the threshold of a second value of the ideal parallel resistance,wherein the first value is obtained for the first one of the pluralityof series-coupled heater elements and the second value of the idealparallel resistance is obtained for the second one of the plurality ofseries-coupled heater elements, wherein selecting the identity isperformed upon determining that the measured parallel resistance iswithin the threshold of the first value of the ideal parallelresistance, selecting another one of the plurality of identities of thesecond one of the plurality of series-coupled heater elements upondetermining that the measured parallel resistance is within thethreshold of the second value of the ideal parallel resistance.
 9. Themethod of claim 1, wherein the first one of the plurality ofseries-coupled heater elements includes a plurality of sub-heaterelements, the method further comprising: receiving from the one or moresensors a plurality of measured parameters of the sub-heater elementsafter selecting the identity of the first one of the plurality ofseries-coupled heater elements; calculating a measured parallelsub-resistance of the plurality of sub-heater elements from the measuredparameters of the plurality of sub-heater elements; determining whetherthe measured parallel sub-resistance is within a range from a firstvalue of an ideal parallel sub-resistance or within the range from asecond value of the ideal parallel sub-resistance, wherein the firstvalue of the ideal parallel sub-resistance is obtained for one of theplurality of sub-heater elements and the second value of the idealparallel sub-resistance is obtained for another one of the plurality ofsub-heater elements; and selecting an identity of the one of theplurality of sub-heater elements from a correspondence between aplurality of identities of the sub-heater elements and the measuredparallel sub-resistance, wherein the selection of the identity of theone of the sub-heater elements facilitates identification of asub-portion of the gas heater channel having the fault.
 10. The methodof claim 9, wherein selecting the identity of the one of the sub-heaterelements is performed upon determining that the measured parallelsub-resistance is within the range from the first value of the idealparallel sub-resistance, selecting another one of the plurality ofidentities of the other one of the sub-heater elements upon determiningthat the measured parallel sub-resistance is within the range from thesecond value of the ideal parallel sub-resistance.
 11. The method ofclaim 1, wherein the portion includes the connector between the firstone of the series-coupled heater elements and the second one of theplurality of series-coupled heater elements, or a connection mediumbetween the first one of the plurality of series-coupled heater elementsand a third one of the plurality of series-coupled heater elements, or acombination thereof.
 12. The method of claim 1, wherein each of theplurality of series-coupled heater elements has a first node and asecond node, wherein the parameters are measured by connecting a currentsensor to the first node of the first one of the plurality ofseries-coupled heater elements and by connecting a voltage sensor to thefirst and second nodes of the plurality of series-coupled heaterelements.
 13. The method of claim 1, wherein each of the plurality ofseries-coupled heater elements includes a resistor, wherein the gasheater channel includes a gas pipe configured to supply the one or moregases to the plasma chamber for processing a wafer within the plasmachamber.
 14. The method of claim 1, wherein the gas supply includes agas source configured to store the one or more gases.
 15. The method ofclaim 1, wherein the plasma chamber is configured to couple to animpedance matching circuit, wherein the impedance matching circuit isconfigured to couple to one or more radio frequency (RF) generators forreceiving one or more RF signals from the corresponding one or more RFgenerators.
 16. A method for determining a fault in a gas heaterchannel, comprising: receiving from one or more sensors measuredparameters associated with a first plurality of heater elements of thegas heater channel, wherein the gas heater channel is configured totransfer one or more gases from a gas supply to a plasma chamber;calculating a measured parallel resistance of the first plurality ofheater elements from the measured parameters associated with the firstplurality of heater elements; comparing the measured parallel resistanceof the first plurality of heater elements to an ideal parallelresistance of the first plurality of heater elements of the gas heaterchannel; determining based on the comparison that the first plurality ofheater elements is operational; receiving from the one or more sensorsmeasured parameters associated with a second plurality of heaterelements of the gas heater channel, wherein the second plurality ofheater elements are coupled in series to form a plurality ofseries-coupled heater elements, wherein a first one of the plurality ofseries-coupled heater elements is coupled via a connector to a secondone of the plurality of series-coupled heater elements; calculating ameasured parallel resistance of the plurality of series-coupled heaterelements from the measured parameters associated with the plurality ofseries-coupled heater elements; comparing the measured parallelresistance of the plurality of series-coupled heater elements to anideal parallel resistance of the plurality of series-coupled heaterelements of the gas heater channel; determining based on the comparisonthat the plurality of series-coupled heater elements is inoperational;and selecting an identity of one of the heater elements of the pluralityof series-coupled heater elements from a correspondence between aplurality of identities and the measured parallel resistance of theplurality of series-coupled heater elements, wherein the selection ofthe identity facilitates identification of a portion of the gas heaterchannel having the fault.
 17. The method of claim 16, wherein one of theheater elements of the first plurality of heater elements is configuredto connect to another one of the heater elements of the first pluralityof heater elements.
 18. The method of claim 16, further comprising:determining whether the measured parallel resistance of the plurality ofseries-coupled heater elements is within a threshold of a first value ofthe ideal parallel resistance of the plurality of series-coupled heaterelements or within the threshold of a second value of the ideal parallelresistance of the plurality of series-coupled heater elements, whereinthe first value of the ideal parallel resistance of the plurality ofseries-coupled heater elements is obtained for the one of the heaterelements of the plurality of series-coupled heater elements and thesecond value of the ideal parallel resistance is obtained for anotherone of the heater elements of the plurality of series-coupled heaterelements, wherein selecting the identity is performed upon determiningthat the measured parallel resistance of the plurality of series-coupledheater elements is within the threshold of the first value of the idealparallel resistance of the plurality of series-coupled heater elements,selecting another one of the plurality of identities of the other one ofthe heater elements of the plurality of series-coupled heater elementsupon determining that the measured parallel resistance of the pluralityof series-coupled heater elements is within the threshold of the secondvalue of the ideal parallel resistance of the plurality ofseries-coupled heater elements.
 19. A system for determining a fault ina gas heater channel, comprising: an alternating current (AC) sourceconfigured to generate AC power; a rectifier coupled to the AC sourceand configured to convert the AC power into pulsing direct current (DC)power; a transistor; a gate drive coupled to the rectifier and to thetransistor and configured to drive the transistor; a channel of heaterelements, wherein the heater elements are coupled in series to form aplurality of series-coupled heater elements, wherein a first one of theplurality of series-coupled heater elements is coupled via a connectorto a second one of the plurality of series-coupled heater elements; acurrent sensor coupled to the transistor and to the plurality ofseries-coupled heater elements and configured to sense a currentprovided to the plurality of series-coupled heater elements, wherein thecurrent is provided when the transistor is driven, wherein each of theplurality of series-coupled heater elements has a first node and asecond node; a voltage sensor coupled to the first node of the pluralityof series-coupled heater elements and the second node of the pluralityof series-coupled heater elements and configured to measure voltageacross each of the plurality of series-coupled heater elements; aprocessor coupled to the voltage sensor and the current sensor, theprocessor configured to: receive the voltage measured by the voltagesensor and the current sensed by the current sensor; calculate aparallel resistance of the plurality of series-coupled heater elementsfrom the voltage and the current; determine whether the calculatedparallel resistance is within a pre-determined threshold of an idealparallel resistance of the plurality of series-coupled heater elements;determine that a portion of the channel is inoperational upondetermining that the calculated parallel resistance is not within thepre-determined threshold of the ideal parallel resistance; and select anidentity of the first one of the plurality of series-coupled heaterelements from a correspondence between a plurality of identities and thecalculated parallel resistance, wherein the selection of the identityfacilitates identification of the portion of the channel having thefault.
 20. The system of claim 19, wherein the processor is furtherconfigured to: determine whether the calculated parallel resistance iswithin a threshold of a first value of the ideal parallel resistance orwithin the threshold of a second value of the ideal parallel resistance,wherein the first value is obtained when the first one of the pluralityof series-coupled heater elements is inoperational and the second valueof the ideal parallel resistance is obtained when the second one of theplurality of series-coupled heater elements is inoperational, whereinthe processor is configured to select the identity is performed upondetermining that the calculated parallel resistance is within thethreshold of the first value of the ideal parallel resistance, whereinthe processor is configured to select another one of the plurality ofidentities of the second one of the plurality of series-coupled heaterelements upon determining that the calculated parallel resistance iswithin the threshold of the second value of the ideal parallelresistance.